A window air conditioner can cool normally while letting outside air through its side panels. Inspect the indoor contact points before adding tape or foam.
QUICK STEPS
If you need the short version, try these steps first.
- Turn the unit off and unplug it.
- Check the sash and locking bracket.
- Inspect accordion panels for tears.
Before you continue, check these safety points.
- Never lean outside to adjust the unit.
- Do not block condenser airflow.
- Stop if the mounting shifts.
Locate the draft from inside the room
Gaps often appear where the accordion frame meets the sash or window trim.
- Turn the unit off and unplug it.
- Check the sash and locking bracket.
- Inspect accordion panels for tears.
- Look for compressed or missing foam.
- Measure accessible gaps and compare approved seals.
- Recheck the unit's support after sealing.
Do not cover drainage or cooling vents
Window units drain condensation outdoors. Blocking weep paths or louvers can cause water damage and overheating.
A rocking unit is a mounting problem
If the sash or bracket moves, stop using the unit and have the support corrected. Tape is not structural support.
Watch for rainwater tracks
Wet drywall below the unit may indicate poor installation slope or flashing, not merely an air gap.
Before you call it done
- The unit is securely supported.
- The side panel is intact.
- Drain openings remain clear.
- All inspection is done from inside.